1. Field of the Invention
The present invention relates to an information storage medium and a method and a system recording data on the same, and more particularly, to an information storage medium, which includes a plurality of recording layers having a layout structure of a lead-in area, a lead-out area, and a user data area to improve a recording speed and recording performance, and a method and a system recording data on the same.
2. Description of the Related Art
In general, an information storage medium is used in relation to a non-contact type optical pickup device for recording/reproducing data. A type of optical disk as an example of the information storage medium is divided into a compact disk (CD) or a digital versatile disk (DVD) based on the information recording capacity. In addition, examples of an erasable optical disk include 650 MB CD-R, CD-RW, and 4.7 GB DVD+RW. Furthermore, an HD-DVD having a recording capacity of 20 GB is being developed.
In order to increase the recording capacity, a shorter wavelength is used as a recording light source, and the numerical aperture of an object lens is increased. In addition, a plurality of information recording layers are used. U.S. Pat. No. 5,881,032 issued on Mar. 9, 1999 discloses a DVD-ROM having a plurality of information recording layers.
A sector address structure of a disk having dual information recording layers is shown in FIG. 1A. The disk in FIG. 1A has a first information recording layer L1 and a second information recording layer L2 that have lead-in areas 1a and 2a and lead-out areas 1b and 2b, respectively. On the first information recording layer L1, a first sector address X is increased in a direction from an inner perimeter Rin of the disk to an outer perimeter Rout of the disk. On the second information recording layer L2, a second sector address X′ is increased in a direction from the outer perimeter Rout to the inner perimeter Rin of the disk.
On the other hand, a multi-layered optical disk having more than two information recording layers can be divided into an opposite track path (OTP) and a parallel track path (PTP) based on directions of recording/reproducing data on/from the disk. The OTP reproduces data from the first information recording layer L1 in a direction from the inner perimeter Rin to the outer perimeter Rout and reproduces data from the second information recording layer L2 in a direction from the outer perimeter Rout to the inner perimeter Rin, as shown in FIG. 1B. In other words, the track spiral directions of the OTP optical disk are alternately formed on each of the information recording layers. In addition, FIG. 1C denotes an OTP multi-layered optical disk having first through fourth information recording layers L1, L2, L3, and L4. In the OTP multi-layered optical disk, first through fourth lead-in areas 1a, 2a, 3a, and 4a and first through fourth lead-out areas 1b, 2b, 3b, and 4b are alternately formed at the inner perimeter regions and the outer perimeter regions of the first through fourth information recording layers L1, L2, L3, and L4 of the disk, respectively. The data is reproduced from the first information recording layer L1 in the direction from the inner perimeter Rin to the outer perimeter Rout, from the second information recording layer L2 in the direction from the outer perimeter Rout to the inner perimeter Rin, from the third information recording layer L3 in the direction from the inner perimeter Rin to the outer perimeter Rout, and from the fourth information recording layer L4 in the direction from the outer perimeter Rout to the inner perimeter Rin
FIG. 2 denotes a PTP dual-layered optical disk having a first information recording layer L1 from which data is reproduced in a direction from an inner perimeter Rin to an outer perimeter Rout and a second information recording layer L2 from which data is reproduced in a direction from the inner perimeter Rin to the outer perimeter Rout. In other words, track spiral directions of the information recording layers are the same. A first lead-in area 1a is formed at the inner perimeter portion of the first information recording layer L1, a first lead-out area 1b is formed at the outer perimeter portion of the first information recording layer L1, a second lead-in area 2a is formed at the inner perimeter portion of the second information recording layer L2, and a second lead-out area 2b is formed at the outer perimeter portion of the second information recording layer L2.
In the case of a multi-layered recordable disk, the lead-in areas 1a, 2a, 3a, and 4a and the lead-out areas 1b, 2b, 3b, and 4b include information about the disk and various conditions about recording. Accordingly, user data can be properly recorded and reproduced when reproducing the user data from the lead-in areas 1a, 2a, 3a, and 4a and the lead-out areas 1b, 2b, 3b, and 4b. 
When the amount of the data to be recorded on the multi-layered information storage medium is smaller than the capacity of the information recording layers, there is an empty area on at least one information recording layer.
A method of processing the empty area of the information recording layer should be determined for various information storage media. FIG. 3A illustrates a single-layered recordable information storage medium, and FIG. 3B illustrates a dual layered recordable information storage medium. The locations and the capacities of lead-in areas, lead-out areas, and user data areas are fixed.
On the other hand, the data may be recorded on the entire area of the data area of the first information recording layer L1 and on a portion of the data area of the second information recording layer L2, as shown in FIG. 4. When a beam passes through the first information recording layer L1 and the second information recording layer L2, the beam may pass through a portion L1R of the first information recording layer L1 on which the data is recorded and a portion L2N of the second information recording layer L2 on which the data is not recorded, or the beam may pass through portions L1R and L2R of the first and second information recording layers L1 and L2 on which the data is recorded. Thus, when the reproducing conditions of the areas through which the beam passes are different, a reproducing characteristic may be affected.
As described above, when determining the layout of an information storage medium, the consistency and unity with the information storage medium of a particular type should be considered and the reproducing performance of a multi-layered information storage medium should be considered. In addition, it is important to improve a recording speed according to the increase of a recording capacity.
For example, a conventional recordable DVD has a single information recording layer and a capacity of 4.7 GB. On the other hand, a conventional DVD-ROM has a capacity of 8.5 GB and dual information recording layers. However, in order to back up the data from a DVD-ROM having a capacity of 8.5 GB, a recordable DVD having the same capacity is required. In addition, a method of efficiently recording data is required to reduce a back-up time of the data.